Observation of $B^{+} \rightarrow p\bar{\Lambda} K^+ K^-$ and $B^{+} \rightarrow \bar{p}\Lambda K^+ K^+$

TL;DR

This paper reports measurements of branching fractions for specific B+ meson decays involving baryons and mesons, using a large data sample from the Belle detector, and provides evidence for some decay modes while setting upper limits for others.

Contribution

First measurement of several B+ decay modes involving baryons and mesons with detailed branching fractions and evidence for certain channels.

Findings

Measured branching fractions for multiple decay modes.

Found evidence for ext{B}^+ ightarrow ar{ ext{p}} ext{Λ} K^+ K^-, ext{B}^+ ightarrow ext{η}_c ext{D}^+ + c.c., and ext{B}^+ ightarrow ext{Λ} ar{ ext{p}} K^+ K^+.

Set upper limits for ext{J/ψ} ext{Λ} K^+ and ext{Λ} ar{ ext{K}}^0 decays.

Abstract

We report the study of \OK \ and \SK \ using a $772 \times 10^6$ $B\bar{B}$ pair data sample recorded on the $\Upsilon({\rm 4S})$ resonance with the Belle detector at KEKB. The following branching fractions are measured: $\mathcal{B}$(\OKPHSP) $=$ $(4.22^{+0.45}_{-0.44}\pm 0.51)\times10^{-6}$, $\mathcal{B}$(\SKPHSP) $=$ $(3.81^{+0.39}_{-0.37} \pm 0.45)\times 10^{-6}$, $\mathcal{B}$(\ETACD+c.c.) $=$ $(2.91^{+0.37}_{-0.35}\pm 0.36)\times 10^{-3}$ and $\mathcal{B}$(\PLPHI) $=$ $(8.18 \pm 2.15 \pm 0.79)\times10^{-7}$, where c.c. denotes the corresponding charge-conjugation process. The intermediate resonance decays are excluded in the four-body decay measurements. We also found evidences for $\mathcal{B}$(\ETACS+c.c.) $=$ $(3.59 \pm 1.52 \pm 0.47) \times 10^{-3}$ and $\mathcal{B}$(\LLKO) $=$ $(2.30 \pm 0.65 \pm 0.25) \times 10^{-6}$. No significant signals are found for \JPSIS+c.c. and \LLKS \ ; we set the 90\% confidence level upper limits on their decay branching fractions as $< 1.85\times10^{-3}$ and $< 2.14\times10^{-6}$, respectively.